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<divisions. Itis not likely that the fluviatile and suberial 
agencies, however prolonged or intense, would altogether 
destroy the older deposits in the formation of the later 
rocks; and it is reasonable to assume, where there are no 
sudden breaks, such as occur elsewhere, by the sudden alter- 
nation of Marine and Terrestrial formations, that the 
transition, as even now indicated by the fossil flora, would 
be very gradual in the limited basins where sediments 
were deposited, which, probably, were again and again partly 
re-distributed, as successive formations in gradually lessening 
areas. Nor can it be reasonably expected, where such separate 
minor basins are so intimately related to each other, that 
marked breaks in the chain of organic life, should be apparent, 
and therefore it would be extremely hazardous to assume 
that the identity of even one or two species in separate basins 
was sufficient evidence to mark synchronism between them, 
especially so where the associated prevailing forms of the one 
basin differ materially from the other. On the other hand, 
different conditions, such as soil or altitude, might account 
for a considerable amount of difference between two widely 
separate basins, although the evidence in this latter direction 
wonld not be quite satisfactory where the two separate basins 
were only separated by a line from slightly unconformable 
beds in juxtaposition. 
From considerations such as these, and while willing to 
recognise the fact that all the European subdivisions, may 
be represented by equivalents in Tasmanian Rocks, I 
still think it would be altogether unscientific to expect 
that the many little groups of our Mesozoic rocks, as 
a whole, will show the faintest correspondenc with 
the ternary sub-groups (Triassic, Jurassic, Cretaceous), 
as such. To attempt to make corresponding divisions in 
Tasmania, with our present knowledge respecting stratigraphy 
and paleontology, would be purely artificial and altogether 
misleading. In the meantime, I am of opinion that the 
stratigraphic and organic characteristics of each separate 
basin or group of rocks should first be carefully and fully 
marked and related to each other. Until some satisfactory 
limits have been determined, I think you will agree with me 
that it would be rash to refer the various local basins of 
Mesozoic age under any of the great sub-division groups of 
Europe. In harmony with these observations and as a 
practical contribution to the materials necessary to aid in the 
proper classification and correlation of our Mesozoic rocks, L 
have prepared a table, showing the distribution of all the 
Tasmanian plants of the system known to me, in which are 
included a considerable number of forms not hitherto known 
as occurring in Tasmanian rocks. 
